This cake is a chocolate lovers dream. It's dark, rich, and moist. It's so amazing that it mast be some kind of magic!
Preheat oven to 350 degrees F (175 degrees C). Grease and flour two 9 inch round cake pans or one 9x13 inch pan.
In a large bowl, combine flour, sugar, cocoa, baking soda, baking powder, and salt. Make a well in the center.
Add eggs, coffee, buttermilk, oil, and vanilla. Beat for 2 minutes on medium speed. The batter will be thin. Pour into prepared pans.
Bake at 350 degrees F (175 degrees C) for 30 to 40 minutes, or until a toothpick inserted into the center of the cake comes out clean.
Cool for 10 minutes, then remove from pans and finish cooling on a wire rack. Fill and frost as desired.